Greenhouse Thrips – Heliothrips haemorrhoidalis
Greenhouse Thrips: Appearance, Territory, Damage and Life
Latin name: Heliothrips haemorrhoidalis
Appearances: The greenhouse thrips’ head and thorax turn black when it reaches adulthood, and its belly transforms from yellow to dark brown. The color changes are delayed in cold temperatures. The antenna has eight segments, and the legs are still a bright yellow color. Since the greenhouse thrips reproduces parthenogenically—that is, without mating—males are rarely observed. It has a weak sense of direction and prefers to stay on the plant’s foliage in the shade.
Host plants: This thrips is particularly common on crotons in Florida, but it has also been discovered on many other ornamentals, including ardisia, Aspidium sp., avocado, azalea, Coleus sp., Crinum sp., dahlias, dogwood, ferns, Ficus nitida, guavas, hibiscus, natal plum, magnolia, mangoes, maple
Territory: In tropics and subtropics, H. haemorrhoidalis is widely distributed. It was hypothesized that this species originated in a tropical region before being transported to other parts of the globe.
Damage insect caused: Citrus trees’ leaves and fruit are damaged by greenhouse thrips, yet no leaves fall off. The fruit damage may take the form of clearly defined depression patches, frequently with erratic reticulation. When fruit is young, this kind of damage happens. On mature fruit, the damage is not clearly visible and seamlessly blends into the sound peel. Additionally damaging avocados, the greenhouse thrips is a significant pest of that fruit in New Zealand and other places.
Life cycle and habits: Their life cycle includes egg development, two nymphal stages, a non-feeding prepupal stage, and a pupal stage, same like other thrips species. When living in favorable temperate settings, a single thrips may create up to seven generations, and when living in favorable tropical conditions, it could produce more than twelve generations. A H. haemorrhoidalis lives for about a month on average. The eggs laid by the female H. haemorrhoidalis are autonomous and are found on or beneath leaves. If there are exposed regions, the females would transport their eggs using feces and secretions from the auxiliary gland. If the environment is between 26 and 28 degrees Celsius, the eggs will hatch after 14 to 15 days, and between 16 and 22 degrees Celsius. Larvae in their first instar have an adult-like structure. Their bodies range in length from 430 to 480 micrometers. Their ganglia are more tightly packed together than in adults, and they only have two spiracles. The size and color of the second instar larvae are around 1.1 mm.