Lesser Angle-wing Katydid (Microcentrum retinerve)
- Katydids are related to crickets and grasshoppers and possess large back legs for jumping. Unlike grass hoppers they have extremely long and thin sensitive antenna which earns them the name of ‘long horned grasshoppers.’
- Many Katydids resemble green leaves accentuated by prominent green veins on the outer wings.
- Most katydids eat plant material specially leaves. A few species prey on insects or scavenge.
- Mostly tree dwellers, these insects become clumsy and many fall to the ground as the weather goes chilly.
- This specimen of the lesser angle Katydid, Microcentrum retinerve, was observed in the warmth of a home on a cold December night of 2024.
- Distribution of Katydids in the Indian subcontinent has not been adequately reported. I have not been able to access to a report describing this species from the Indian subcontinent. M. retinerve has been reported as an American Species.
- I have identified this specimen as M. retinerve but would be open to viewers correcting me on this.
- Microcentrum retinerve is a species of Katydids which is also referred to as the lesser angle winged Katydid. It is one of the two closely resembling species of Katydids, M. rhombifolia and M. retinerve.
- Ranging from 44-53 mm, M retinerve is slightly smaller that M. rhombifolia and is a general resident of deciduous forests often calling from the top of trees. They are attracted to light.
- With biting jaws, many katydids eat plant material specially leaves. A few species prey on insects or scavenge.
- M. retinerve males, unlike M. rhombifolia males, have a dark brown prominent area on the pronotum (just behind the head on the dorsal side). Females may not have this brown area. This specimen appears to be a female. One can notice the upwardly curved oviposter at the end of the abdomen which is used to deposit eggs either in the soil or on the branches of trees or on twigs of grasses. The oviposter is less rounded in M. rhombifolia. The central tooth in the pronotal disc as a in M. rhombifolia is also absent here.
- Katydids possess specialised hearing organs called the tympana on their front legs and small holes known as auditory spiracles on their hind legs that help them to perceive sound that surpasses the range of human hearing and provides them remarkable advantage in survival. The insect raises and moves its legs to catch sound signals.
- All ‘tarsi’ have four segments instead of 03 as in crickets.
- Sound is produced as they rasp their wings together. Wings are often positioned to amplify the sound. Males sing to attract the females and claim territories. In some species females may sing too. Calls are unique to each species. Songs may end at the onset of winters.
- This specimen exhibits a decapitated right front leg. Regeneration of excised segments has been reported. The size and development of the new limb varies with the age of the insect at excision.
- Females deposit eggs in soil, plant stems or tree barks in late summer or autumn. The adults die off and the eggs hatch into nymphs in the following spring. The nymphs generally resemble the adults.
- The males, at the end of copulation, present their spermatophores to females along with additional protein attaching to the spermatophores. The protein is eaten by the female, only after she has received the spermatophores position externally on her genitalia. This protein called the spermophylax is a male mating investment which is gifted to the females after copulation. The functions of the spermophylax are to deter females from premature removal of the sperm containing ampulla. Feeding on spermophylax is a nutrient resource for the females helping it to develop her eggs. It also acts as a source of compounds that influence female behaviour to increase male evolutionary fitness. The production of spermophylax may require as much as 40% of the males weight and the presentation of this protein improves the chances of reproductive success. In species that produce large food gifts, the female is the one that seeks a mate. Males with a large food packet often mate once or twice in the life time.
©Srimaa Communication
Credits- Dr. Yashpal Singh, Mrs. Neena Singh, Manoj Kumar Yadav