A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
The earlier instars of this species looked very different from the adults. Nymphs were black in body color with reddish orange accent markings and black antennae and wing pads. Once a lubber molted into the adult stage it did not mate until the body colors darkened. Distinguishing characteristics of this intermediary stage between nymph and sexually mature adult included a pinkish purple body color, light brown tegmina, and bright pink accent markings. Sexually mature adults were dark purple and had tegmina of similar color with cherry red wings and body markings that were black and outlined in dark pink. Both sexually mature (imago) and intermediary phase individuals had orange antennae with black tips.
These T. reticulata were sexually dimorphic, and adult females were visually distinguishable due to their ovipositor and larger size. Average female femur length was 32.1 +/- 1.8 mm and average male femur length was 28.2 +/- 1.9 mm.
A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
The field site in the Boca del Drago region (09°24'95"N and 82°19'63"W) was an area disturbed by a road to the south (paved in 2002), the Caribbean Sea to the north, and two fenced pastures on the west and east sides. The enclosed area was at sea level and was 4.5 X 48.9 meters with a ground cover of nonnative grasses, some small bushes and trees, and herbs that included Hymenocallis sp..
The geographic area is considered part of the low-latitude climate, which is one that remains humid all year and receives heavy rainfall in all months (Strahler and Strahler, 1984). From May to mid-December there is a period of heavier rains that is designated the rainy season, but the difference between the rainy and dry precipitation accumulation is very minimal. The Boca del Drago region has an annual rainfall of approximately 4,000 mm, and during the rainy season the average daytime temperature is 30°C (P. Lahanas, pers. comm.).
These brightly colored lubber grasshoppers were observed at several areas in the region, but they were not seen in the rainforests, swamps, or along the sandy beaches, although they could be found on the periphery of these areas where grasses were likely to grow. Nymphs were never found in regions without patches of the Hymenocallis lily.
A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
The individuals in the population I observed were generalists and fed on every green plant available in the study site. These grasshoppers were also documented feeding on Hibiscus sp. flowers and once on a noni (Morinda citrifolia) fruit. Both nymphs and adults feed on Hymenocallis sp., although nymphs were never observed eating any other type of plant matter. Adults often ate the dried or damaged edges of plants before feeding on the more turgid and healthy material and occasionally drank from pooled water on the leaves.
A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
These lubbers hopped and quickly traveled away from a pursuer, often heading for any tall, stationary item that they could climb. Males could travel short aerial distances, but flight was very limited. The females did not fly, although they would snap their wings while jumping if threatened. Some grasshoppers lowered their bodies closer to their perch if pursued from above and would cling tenaciously to it when forcefully removed. On occasions when mating pairs were collected several hours after dark, they would drop from their perches as opposed to the daytime tendency to climb as high as possible. Once an insect was captured it would almost always regurgitate, defecate, and physically struggle and kick with the spiny rear legs. These insects could also release a foamy, odorous secretion from their spiracles. Two males were seen to raise their tegmina and bright wings while curling their abdomens up dorsally and moving with large, quick steps (a photograph of this position can be found on the closely related Romalea microptera EOL page: click here). Most T. reticulata would bite if given the opportunity, and an occasional male would snap his wings when struggling for release.
Insects were rarely documented displaying disturbance behavior towards one another, except in mating situations. Approximately 14.5% of the mated males and 8.7% of the unmated males were injured; however, this difference was not significant (X2=1.0; df=1; p=0.32). It is also important to note that the grasses of the study site were cut with a machete in order to reduce habitat conducive for small, biting Dipterans. It is likely that most of the injuries I noted were sustained during this time.
A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
Copulation attempts often proceeded without any signaling or display from the male. A male would slowly approach a female, and if he entered the female’s line of vision, she would begin vigorously waving her large rear legs and brightly colored antennae. Such displays either caused the male to retreat or to attempt to mount. Females were always active when mounting was attempted, and they would kick at mounting males and move away from them if possible. After females were mounted they would contract their abdomens and/or perform a sharp “ticking” motion from side to side that often unseated the males. Usually when single males were in the vicinity of this dynamic behavior they would join in the skirmish, traveling as far as several feet to reach the mating pair even when a solitary female was present and/or in closer range.
Males approached females with waving antennae and a great deal of palp movement. The initial male would scramble to grasp a female’s pronotum with his front pair of legs, and once secured he would stretch his abdomen towards her genital vent. Some mating males would snap their wings—displaying the bright red coloring and making a loud sound—at the approach of other males. Competing males attempted to displace the current male by bodily pushing into copulatory position. Males would kick at one another and frequently they would both fall from the female, leaving her open to attack from additional males, and up to four males were documented on top of a single female. A female did not have to be present for a male to mount another male, and when this behavior occurred, males usually leapt off fairly quickly. However, once, after nightfall, a male was observed to stay astride another male for several hours.
Following genital contact, most females made a few additional leg stokes towards the genitalic coupling before subsiding for a period of time, after which they would begin struggling again. Females intermittently displayed agonistic behaviors such as directing ticking and/or kicking towards the mounted male, and I observed such behavior to precede all separations not caused by rival males. All observed separations appeared to be a result of rival male interference or a successful female aggressive interaction, and no males were ever seen to dismount without agonistic behavior.
The lubbers would not commence mating in captivity (a large tank with items similar to the natural environment). On one occasion, after several days of containment with no interaction, a male immediately attempted to mount the same female once released into the field. Males remained with females during the capture, travel, and placement into captivity.
A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
Mating started around the beginning of July, and 39% (27 of 69) of mated males and 46% (26 of 57) of mated females were documented with multiple partners throughout the study period, although this difference was not significantly different (X2=2.0; df=1; p=0.10). Scan samples showed that 31% (351 of 1132) of lubber daily activity was spent in mating behavior.
The ratios of male to female lubbers that were taken progressively throughout the study were 1:1, 0.91:1, and 1.6:1. A greater percentage of the male population had copulated in comparison to the female population (54.8% to 45.2%), but these results were not significantly different (X2=2.3; df=1; p=0.13), and there was no correlation between the sizes of the two members of a mating pair (i.e., larger males with larger females; n=109; r=0.08; p=0.40). However, mated females were significantly larger than unmated females (t=-3.6; n1=69; n2=55; df=121; p=0.001), but there was no size difference between unmated and mated males (t=.79; n1=68; n2=56; df=122; p=0.94). There was also no significant correlation between the date of a copulation and the duration (n=102; r=0.13; p=0.20).
The average duration for field copulations was 281.2 ± 358.9 minutes (n=27; max=1624 minutes; min=2 minutes). The mean duration for captive mating pairs was 548.6 ± 478.3 minutes (n=74; max=2869 minutes; min=56 minutes). The copulations I monitored in captivity were significantly longer than those documented in the field (Mann-Whitney test; n1=23; n2=70; w=519; p≤0.001). There was a weak but insignificant negative correlation between a male’s initial mating time with a female and the number of partners she subsequently had (n=35; r=-0.31; p= 0.07). There was no correlation between female size and duration (n=71; r=0.07; p=0.60), or male size and duration (n=72; r=-0.06; p=0.62).
A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
All observed molts occurred diurnally and took place at all times of the day, although most lubbers seemed to molt in the earlier part of the morning. Molting nymphs used their tarsi to secure themselves to a substrate before they began the process of splitting the old cuticle. The most common method was for the insect to secure itself onto the substrate and split the cuticle along the dorsal midline and push out; however, some insects would hang perpendicular from a substrate, using the inversion to aid the process. If insects performed inverted molts, a consequence was that they could fall to the ground once freed, and some insects appeared to bypass this outcome by angling themselves towards a substrate that was near enough to clasp once molting was completed. Once the hind limbs were freed from the old exoskeleton, the animal would usually grasp the substrate until the new cuticle hardened. Immediately after the last molt the new adults had a pinkish buff color with neon pink markings and brightly colored pink, purple, and yellow wings.
A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
Three females were observed ovipositing over the course of this study. One of these occasions was in the field and the other two were in captivity. Both captive ovipositions occurred after dark and the field observation was noted in the afternoon, well before sunset. The captive ovipositions occurred on the 18th and 26th of July and the field oviposition occurred on the 27th of July. The field site was underneath a Hymenocallis lily on a sunny day following a heavy rainstorm. There was not much herbaceous ground cover, but there was leaf litter. In captivity the females buried the ootheca approximately 5 cm deep, with the top of the pod about 2 cm beneath the sand. A pinkish white foam substance was the last material to be deposited and underneath that was a dark, thin layer that enclosed the eggs. The egg pod was approximately 9 X 45 mm and weighed 0.004g. One pod contained 43 black, elliptical eggs, and another had 28 eggs. After a female laid her eggs the ovipositor would be coated with a bright white substance, and this effect allowed me to determine whether or not a female had oviposited recently.
A population of Taeniopoda reticulata in the region of Boca del Drago on the island of Isla Colon in the Bocas Del Torro Archipelago of Panama: June 15 – July 31, 2004.
No hatchlings were seen over the month and a half study, and near the start of July nymphs became increasingly rare. The interval for observed instar length was 14-16 days.
A small red mite was observed on a majority of the population. There was never any evidence of vertebrate predators, which makes sense since the species is aposematically colored, but a dead female was once covered in an unidentified species of ant.
