Thripidae: Panchaetothripinae

Biology

Panchaetothripine species are all leaf feeding, only an occasional adult being found in flowers. Many of the most common species in this subfamily are associated with older, senescing leaves, not with young, apical leaves. Despite this, some species in the genus Caliothrips can be damaging to seedlings of various crops in the tropics, including cotton. There is considerable behavioural diversity within the subfamily. Some species, such as the greenhouse thrips, Heliothrips haemorrhoidalis, are particularly sluggish, and scarcely move when distrurbed. In contrast, other species are more active and jump readily when disturbed, including the red-banded cacoa thrips, Selenothrips rubrocinctus, and species of Caliothrips and Retithrips.

Diversity

A total of about 125 species in 35 genera are currently recognised in this subfamily. Many of these are dark brown insects, often with banded wings. However, species of Aoratothrips and Zaniothrips are remarkable for being white in colour, although still with conspicuously reticulate body surfaces. Some species have complex structures in the metathorax or the coxae, that are probably associated with muscles involved in jumping. Identification keys to most of the genera and species were provided by Wilson (1975), and a phylogenetic analysis based on morphological characters was provided by Mound et al. (2001).

Bhatti (2006) erected a series of new higher taxa, including several families for genera here considered members of the subfamily Panchaetothripinae. These were the Retithripidae, Rhipiphorothripidae, Caliothripidae, and Panchaetothripidae, each for a single genus, Parthenothripidae for two small genera, Tryphactothripidae for seven genera, and Heliothripidae for the remaining 24 Panchaetothripinae genera. This series of decisions was based on particular character states of adults, but did not include larval characters. Larval Panchaetothripinae, including Retithrips and Rhipiphorothrips, have a characteristic body form with the tenth abdominal segment tubular, and their chaetotaxy is different from that of species in Dendrothripinae, Sericothripinae and Thripinae (Heming, 1991). The smaller of these family groupings is supported by one or more distinctive autapomorphies that do not help in estimating evolutionary relationships, and there is considerable overlap in character states between the larger of the two proposed families.

Distribution

Most Panchaetothripinae are found in the tropics, although a few are pests in greenhouses of temperate countries, including the greenhouse thrips from South America, Heliothrips haemorrhoidalis, and two species of the African genus Hercinothrips. There are at least three genera endemic to South America, two to Africa, two to Australia and one even to New Zealand. In contrast, Caliothrips has species in many different warmer parts of the world, and Astrothrips and Helionothrips are both widespread in the Old World tropics.

Panchaetothripinae Keys

Subfamilies A-Z