Hemipepsis convexa (Bingham 1890)

Hemipepsis convexa (Bingham)

This rather large wasp has a wide distribution in Sri Lanka, and appears to be the most common species of the genus in that country. It occurs in all three ecological zones at localities from near sea level to an altitude of about 700 m with an average annual rainfall ranging from 1000 to 5000 mm. The species was described from Sri Lanka, but it is known to occur in southern India from near sea level to 1050 m. Specific localities at which we captured it in Sri Lanka are as follows.

Mannar District: Ma Villu, Kondachchi and 0.8 km NE of Kokmotte Bungalow, Wilpattu National Park

Anuradhapura District: Padaviya

Trincomalee District: Trincomalee, China Bay

Amparai District: Lahugala Sanctuary and Inginiyagala

Matale District: Kibissa near Sigiriya

Kandy District: Hasalaka, Thawalamtenne, and Kandy, Udawattakele Sanctuary

Colombo District: Labugama Reservoir and Mirigama Scout Camp

Ratnapura District: Weddagala, Gilimale, and Belihul Oya

Badulla District: Ella

Monaragala District Angunakolapelessa

Galle District: Kanneliya

Matara District: Deniyaya

NESTING BEHAVIOR.—I observed this only once in Udawattakele Sanctuary, at 1512 on 22 September 1980. The wasp, 22 mm long, was finishing the closure of her nest, which was placed on a slight slope in dense jungle against a tree root. She tugged at several large leaves, apparently trying to obtain small fragments to conceal the nest entrance. I captured her in a few minutes, and found that her nest was in the tunnel of the prey spider. The tunnel extended 6.4 cm from the entrance to the terminal cell of the spider. The wasp had filled the tunnel loosely with soil. The cell was 2.5 cm long, 2.0 cm high, and 1.5 cm wide. The bulky spider, 21.5 mm long, was thoroughly paralyzed and had been placed on its back with the cephalothorax toward the inner end of the cell. The slightly curved egg, 2.9 mm long and 0.9 mm in diameter, was placed transversely toward the anterior end of the abdominal venter of the spider.

P.B. Karunaratne told me that this spider constructs its nest near the soil surface, lines the tunnel and terminal cell with silk, and makes a funnel-shaped entrance that is camouflaged with pieces of leaf or bark. The wasp must have removed the silk lining the entrance and tunnel before making the closure, for I found a silken lining only at the inner end of the cell.

PREY.—The prey specimens that we collected with the wasps were large, bulky, typical tarantulas belonging to the families Idiopidae and Barychelidae.

The prey at Udawattakele was an adult female idiopid, possibly a species of Scalidognathus Karsch. The other three prey specimens, two from Angunakolapelessa and one from Induruwa Jungle, Gilimale, were immatures of the barychelid spider, Plagiobothrus semilunaris Karsch. I kept one of the prey from Angunakolapelessa alive for some hours. In 6½ hours it recovered enough from thorough paralysis, so that it could flex its legs but was incapable of walking.

PREY TRANSPORT.—I saw a small convexa, 14 mm long, crawling rapidly and excitedly over an almost vertical bank of a dry streambed at Angunakolapelessa at 0943, 27 March 1981. After about five minutes she visited her thorougly paralyzed prey, 13.5 mm long, that was lying venter up on a small flat ledge near the top of the bank. The wasp then disappeared in the leaf litter next to the bank, and returned at 0954. She started to drag off the prey, was frightened by my proximity, and I captured her when she returned 10 minutes later.

At 1415 on this same date T. Wijesinhe saw a small convexa, 12 mm long, walking on the leaf litter in the same dry streambed. She pulled a paralyzed spider, 15.5 mm long, from beneath the leaves, turned it venter down, and, walking backward, dragged the prey while grasping it at the head end.

My last prey record was in the Induruwa Jungle, Gilimale, at 1240, 16 April 1981. A female convexa, 22 mm long, was dragging her thoroughly paralyzed spider, 16.5 mm long, venter up, at the edge of a trail through the dense rain forest.

Williams (1956) noted that the egg of H. ustulata ochroptera was 4.25 mm long, slightly curved, and was attached at one side of the ventral line and at midlength of the spider’s abdomen. He also stated that the cocoon was 35 mm long, and was spun of brown silk with a single wall that was varnished on the inner surface.

Hemipepsis Indiana Wahis

This rather uncommon species occurs in Sri Lanka and southern India (Bengal, Tranquebar in Tamil Nadu, and Coimbatore in Kerala). Within Sri Lanka it has been collected only in the Dry Zone at altitudes from near sea level to 30 m and with an average annual rainfall ranging from 920 to 1000 mm. Our few records of its occurence in Sri Lanka are as follows.

Mannar District: 0.8 km NE of Kokmotte Bungalow, Wilpattu National Park

Anuradhapura District: Padaviya

Hambantota District: Palatupana Tank

PREY HUNTING.—I saw one female, 20 mm long, hunting for a prey in the leaf litter beneath a small malith tree, Woodfordia fruticosa (Lythraceae) in an open field at Palatupana Tank at 0810, 28 September 1977. During her search she flicked her wings rapidly from a position of being folded flat over her abdomen, and antennated the ground incessantly. She paused briefly at a silken burrow entrance, 10 mm in diameter, next to a tree root, antennated the entrance, and then moved on. She returned 10 minutes later and entered the burrow. A minute later I saw a large spider run rapidly down a slight slope from a second entrance on the other side of the root. The wasp lost sight of the spider scurrying away, but picked up its trail five minutes later. I captured the wasp at 0838, after she had clearly lost the spider’s trail.