Greenhouse thrips

H. haemorrhoidalis had gotten their common name of the greenhouse thrips due to the fact that they typically inhabit and are pests in greenhouses. They are polyphagous as they feed on a wide range of different fruits and ornamental plants. Ornamental plants that they infest are the azaleas, calla lilies, chrysanthemums, fuchsia, roses and orchids. They also are considered pests to ferns, palms and vines and vegetative plants as well. Some of the fruits that they were claim to have damaged were those including avocados, persimmons, and kiwis. Larvae and adult H. haemorrhoidalis feed by piercing the epidermal tissue of leaves and fruits and sucking out the cellular content. By feeding on the fruits they do not actually affect the quality of the fruit but rather it affects the cosmetics of the fruit which in turn affects the value of the fruit itself. The nymphs are able to produce a reddish fluid that are deposited on the surface of plants which allows for fungal growth to develop. H. haemorrhoidalis prefers feeding on mature foliage and the nitrogen levels of the foliage actually also plays a role in the thrips' preference. The leaves that have undergone attacks by the greenhouse thrips ended up with a lead-like to silvery colouring.

H. haemorrhoidalis is widely distributed in tropic and subtropic regions. It was speculated that this species was originally from a tropical area and have been introduced to other areas of the world. There is a table listing locations where H. haemorrhoidalis was found at CABI Invasive Species Compendium.

Like other species in the family, Thripidae, they have the typical flattened bodies with wings that are narrow and pointed, and their ovipositors resembles a saw. The Head H. haemorrhoidalis have pale yellow 8-segmented antennae where the last segment narrows to look needle-like. H. haemorrhoidalis have what is described as a hypognathous head that is pointed backwards. The head of the greenhouse thrips is connected to the prothorax by an articular membrance and by cervical sclerites as well. The eyes of the greenhouse thrips are in the form of compound eyes and are made up of 65-70 facets and H. haemorrhoidalis have three ocelli. Another unique thing to the H. haemorrhoidalis is that they have asymmetrical mouthcones that contain an anteclypeus, labrum, labium, paired maxillary stylets and an unpaired left mandible that is well developed. The Body Adults have black thoraxes and yellow to dark brown abdomens, but at the ends of their abdomens, they have an orange coloured tip. Greenhouse thrips have a 10-segmented abdomen. The bodies of the H. haemorrhoidalis are covered with cuticles that have an average thickness of 7.5 micrometers. Their epidermis is made up of flattened cells and have a thickness of 3 micrometers. The forewings of the H. haemorrhoidalis are very narrow and contain few short setae on the veins. The legs of the greenhouse thrips have only a single-segmented tarsi. The body length of an adult H. haemorrhoidalis varies between 1.2-1.8 mm long as adults. The three pairs of legs on an adult is white in colour. H. haemorrhoidalis also have two salivary glands. One pair of the salivary gland is made up of long tubular glands that run parallel to and attached to the midgut by the midgut's basal lamina. This pair is composed of microvillate cells in the distal region and is cuticle-lined in the proximal region. The second pair of salivary glands is confined to the thorax and is made up of ovoid glands. This gland is said to produce a viscous type of secretion while the tubular gland is said to produce a watery type of secretion. The midgut of the H. haemorrhoidalis lacks muscles and the thing that is unique to them is that they have relatively low concentration of ganglia.

Birds, spiders, mantises, ladybugs, lacewings, parasitic wasps

Greenhouse thrips can actually produce a tiny, precise jet of saliva to defend against predators, often deterring much larger foes.