Ammophila laevigata F. Smith 1856

Ammophila laevigata Smith

This small (, 14–20 mm long) member of the sabulosa Group is the most common and widely distributed taxon of Ceylonese Sphecidae. It occurs in both the Dry Zone and the Wet Zone, though more commonly in the former, at altitudes ranging from sea level to approximately 650 m, and in areas receiving average annual rainfall of 860 to 3900 mm. Bohart and Menke (1976:152) list the species as occurring also in India, Thailand, and Vietnam. Both A. laevigata and A. basalis Smith are smaller than A. atripes Smith (, 26–31 mm long). They have clear to lightly infumated wings rather than the yellow () or infuscated () wings of A. atripes. The former species differs from A. basalis in lacking transverse rugulae on the pronotal dorsum and scutum, and in having a broad patch of appressed silvery vestiture along the posterior margin of the mesopleuron rather than no such patch.

COLLECTION LOCATIONS AND DATES.—NORTHERN PROVINCE. Jaffna District: Kilinochchi, 24–27 Jan; Pooneryn, 24–26 Jan, 7 Nov. Mannar District: Ma Villu, Kondachchi, 22–28 Jan, 17–21 Feb, 11–12 Apr, 20 Sep; Marichchukkadi, 26 Jan; 0.5 mi (0.8 km) NE Kokmotte Bungalow, Wilpattu National Park, 22–23 Jan, 25 May; Cheddikulam, 15–16 Jun.

NORTH CENTRAL PROVINCE. Anuradhapura District: Padaviya, 18–21 May, 11–14 Oct, 2–8 Nov; 20 mi (32 km) S Anuradhapura, 19 Jun. Polonnaruwa District: 23 mi (36.8 km) NW Polonnaruwa, 12 Jun.

EASTERN PROVINCE. Trincomalee District: China Bay Ridge Bungalow, Trincomalee, 27–31 Jan, 26 Feb, 8–11 Oct. Amparai District: Ekgal Aru Sanctuary Jungle, 19–22 Feb, 9–11 Mar, 9–11 Jun; Maha Oya, 15 Sep; Lahugala Sanctuary, 13–14 Jun.

CENTRAL PROVINCE. Matale District: Sigiriya, 17–18 Jun; 3 mi (4.8 km) S Naula, 15 Jun. Kandy District: Udawattakele Sanctuary, Kandy, 18–21 Jan, 8–18 Mar, 8–11 May, 16–31 Aug, 1–17 Sep, 27–28 Oct; Aruppola, 14 Apr; Katugastota, 26 Oct; Thawalamtenne, 16–18 Sep; Hasalaka, 16–19 Feb, 30–31 May, 15 Aug.

WESTERN PROVINCE. Colombo District: Colombo, 28–31 Jan; Ratmalana near airport, 13 and 19–21 Jan, 6 Jun; Gampaha Botanic Garden, 28 Jan, 27 Sep, 8 Nov; Labugama Reservoir, 2–4 and 16 Feb, 9 May, 11 Jul, 13–14 and 29 Oct.

SABARAGAMUWA PROVINCE. Ratnapura District: Ratnapura, 25 Mar, 10 Oct; Gilimale, Induruwa Jungle, 5–7 Feb, 13–15 Mar, 19–22 Jun, 10 Oct; Uggalkaltota, 23–26 Jun; Rajawaka, 20 Jun; Kalatuwawa, 6–16 Aug.

UVA PROVINCE. Badulla District: Badulla, 30 Sep. Monaragala District: Angunakolapelessa, 21 Jan; Buttala, 5 Jun; Inginiyagala, 12 Jun, 7–8 Sep.

SOUTHERN PROVINCE. Galle District: Kanneliya section, Sinharaja Jungle, 11–16 Jan. Hambantota District: Palatupana, 18–20 Jan.

The dates of activity at such localities as Ma Villu, Udawattakele Sanctuary, Labugama Reservoir, and Gilimale suggest that the species may breed throughout the year in favorable situations. We observed various details in the nesting cycle near Kokmotte Bungalow on 22 Jan, at Trincomalee on 10 Oct, at Ekgal Aru on 20 Feb, 11 Mar, and 10 Jun, at Hasalaka on 17 Feb, at Labugama Reservoir on 16 Feb and 9 May, and at Angunakolapelessa on 21 Jan. I noted a pair in copula (52576 C) at 1400 hrs, 25 May 1976, on a sand bank along an open jungle trail near Kokmotte Bungalow.

FIELD OBSERVATIONS.—Ammophila laevigata prefers to nest in flat areas rather open to sunlight and in a substrate ranging from sand to rather densely packed sandy loam, sometimes with intermixed small pebbles. The wasps excavated their burrows at angles ranging from almost vertical to 45° to the horizontal. The excavated soil was removed between the underside of the head and the forelegs. After the wasp backed out of the burrow with a load of soil, she flew forward or backward from half a meter to almost a meter and 5 cm above the ground, dropped the soil, and then flew back to the burrow to continue digging. I was unable to ascertain the time required to dig a complete burrow and cell.

We did not observe temporary closure of the burrow entrance when the wasp completed the nest, nor did we witness the customary orientation flight around the burrow before she departed to hunt for prey. However, we observed prey being brought into the nest several times, and each time the caterpillar was placed on the ground near the entrance while the wasp removed the temporary closure.

I watched the first nesting female (21675 C) at Labugama Reservoir on 16 February at 1448. Her nest was in a path of hard-packed sandy loam interspersed with small pebbles. She carried her paralyzed caterpillar, 14 mm long, head first beneath her and set it on the ground near the nest entrance, removed a larger pebble over the entrance and then reached in and brought out several smaller pebbles. Next she came to the entrance head first, reached out and pulled in the caterpillar head first. Either the burrow or the cell was too small because she came out in about a minute, reached in and pulled out the caterpillar, and then excavated several loads of soil, flying backward half a meter to drop each load. She then entered the burrow head first, turned around, came to the entrance and again pulled in the caterpillar head first. At 1457 she began construction of a temporary plug. She searched for a pebble of the proper size to plug the lumen of the burrow, discarding some as being too small, and finally put one of the desired size 1.3 cm below the surface. Then she scratched sand beneath her into the burrow, pressing it down with the front of her head, but not using a pebble to compact the soil. She occasionally interspersed a few pebbles with the sand. The burrow was filled nearly level at 1502 and she spent the next four minutes scratching and smoothing loose sand over the entrance. She then flew to several plants nearby for nectar and I captured her. The closing plug contained about ten tiny pebbles, each 1.0–1.5 mm in diameter, mixed with sand, and then a larger pebble 4–5 mm in diameter. The burrow was almost vertical, 2.5 cm deep and 4 mm wide, and terminated in a horizontal cell 1 cm long and 8 mm high at right angles to the burrow. The cell had a sand plug 2–3 mm thick, within which was a single satyrid caterpillar bearing the wasp's egg attached on the right side between the spiracles of the first two abdominal segments. The egg was slightly curved, 2.8 mm long and 0.7 mm wide.

I observed another female (5976 A) at Labugama Reservoir beginning a nest at 1230 on 9 May. When I returned at 1305 she had completed the nest and constructed a temporary closure. I excavated the nest at 1545 and found that no prey had been stored. The entrance was concealed with loose sand, and the temporary closure contained sand and small pebbles to a depth of 4 mm and then a larger pebble. The burrow went downward for 33 cm at an angle of 75° and terminated in an empty, horizontal subspherical cell about 1 cm in diameter.

On 22 January at 1300 near Kokmotte Bungalow D.W. Balasooriya saw a female (12277 C) flying toward her nest in a sandy path with a light green caterpillar. She alighted near the entrance, set down the caterpillar, removed the temporary closure, entered the burrow head first, turned around, and pulled the caterpillar headfirst into the nest. Balasooriya captured the wasp when she emerged a minute later. The burrow went downward at an angle of 75° and ended in a cell 6.4 cm below the surface. The cell contained a single noctuid caterpillar 18 mm long, bearing the wasp egg on the left side of the third abdominal segment. The egg was slightly curved, 2.7 mm long and 0.7 mm wide.

At Angunakolapelessa P.B. Karunaratne observed on 21 January what was probably storage of the last prey specimen and final closure of the nest (12179 C). At 1400 he noted a paralyzed caterpillar at the entrance of a nest that the wasp had just entered. The nest was in sandy soil in a dry stream bed. The wasp came out of the nest headfirst, grasped the caterpillar at one end and shoved the other end into the burrow. She went into the burrow, shoving the caterpillar ahead of her. A few minutes later she emerged, flew around the entrance in circles, alighted at the entrance, and searched for something to plug the cell. She picked up a piece of charcoal 15 cm from the entrance and carried it into the nest. Then she selected a smaller pellet of hardened earth and pushed it in. She flew around for a minute or two and selected a larger pellet that she carried on the ground to the entrance. It was too large to go into the burrow, so she carried it back to the spot where she had found it. Then she entered the nest headfirst, brought out two pellets of soil, leaving them at the entrance. Probably she removed some obstruction within the nest, for she next flew backward from the entrance, alighted and took the large pellet again. She tried unsuccessfully to place it farther down in the burrow, and brought it back to the surface. She reentered the burrow headfirst, backed out with some soil, and flew backward to drop it. She tried again to get the large pellet into the burrow and was successful in placing it farther down, together with the two smaller pellets removed earlier. Then she removed the larger one again, tried unsuccessfully to place it deeper, and finally carried it away from the nest. Next she placed several more pellets flush with the burrow entrance, and Karunaratne captured her at 1415. The burrow diameter was 6 to 8 mm, and penetrated the ground at an angle of 45° for 2.5 cm. The cell was at right angles to the burrow, 1 cm wide and 2 cm long, and the upper end was only 1 cm below the surface. The charcoal pellet first brought into the nest was at the cell entrance. The cell contained three paralyzed satyrid caterpillars. At the bottom of the cell was a large green one, 16 mm long, bearing the wasp's egg, then a smaller green one, 13 mm long, on top of the first, and then the larger brown caterpillar, 18 mm long, that had been at the nest entrance at 1400. The egg was damaged in transit, but it had been glued on the right side of the second abdominal segment.

Two rather anomalous behavioral patterns were noted. On 10 June at Ekgal Aru Sanctuary Jungle, Karunaratne caught a female A. laevigata (61076 C) as she was digging in her nest. The wasp had been flying backward from the entrance, dropping excavated sandy loam about 0.5 m from the entrance. At the entrance were three paralyzed satyrid caterpillars, 12–20 mm long. Some ants were crawling on and around the prey. He captured the wasp and excavated the nest. The burrow went in at an angle of 45° in sandy loam soil for 3 cm and ended in an empty horizontal cell, 1.8 cm long and 1.3 cm wide. I presume that the caterpillars might have been removed to permit enlargement of the cell. None of the caterpillars bore a wasp egg, and perhaps it might have been removed by the ants before the prey were preserved in alcohol. However, it is also possible that the wasp Karunaratne observed was not the rightful owner, but a second female that had discovered the nest, removed the prey, destroyed the egg, and was about to re-inter the prey, laying her own egg on one of the caterpillars. Tsuneki (1968a: 12–13) reported this behavior by two females of the Japanese A. sabulosa nipponica Tsuneki, also a member of the sabulosa Group. Each wasp excavated the nest of another A. sabulosa nipponica, removed the caterpillar, are the wasp egg, stung the caterpillar, and then replaced it in the nest and oviposited thereon.

The second curious behavior occurred at Ekgal Aru Sanctuary Jungle on 20 February, Balasooriya at 1030 saw a paralyzed caterpillar lying on the ground at the nest entrance just as an A. laevigata female (22077 F) returned with another caterpillar. This wasp (A) entered the burrow, turned around, and pulled in one caterpillar just as another A. laevigata (B) without prey alighted near the entrance. Wasp A in the nest dragged out the caterpillar it had just carried in and chased off wasp B. Then wasp A returned, flew off into the jungle with one of the caterpillars, and flew back in a few seconds without the prey. She then removed the second caterpillar in the same way and returned without it. She brought a pebble from the ground and pushed it into the burrow, and then brought another pebble and pushed it in. She continued plugging the entrance with loose earth at which time Balasooriya captured her. He excavated the nest, found the two pebbles near the entrance, and the cell at the end of a very steep burrow, 6.4 cm below the surface. The subspheroidal cell was about 0.6 mm in diameter and was completely empty. Wasp B did not return to the nest during this period. Possibly, Balasooriya observed the attempted appropriation of the contents of one nest by another individual, as I suggested above in note 61076 C. Another possible explanation for the transport of the two caterpillars into the jungle by wasp A might be because she had a second nest to which they were carried. Tsuneki (1968a:9–10) reported a single female of A. sabulosa nipponica provisioning four nests simultaneously. These, however, were in close proximity, whereas a second nest of wasp A, if it existed, was some distance removed from the first.