Tetragonocephala flava Crawford, 1914

Halbert, Susan E. & Burckhardt, Daniel, 2020, The psyllids (Hemiptera: Psylloidea) of Florida: newly established and rarely collected taxa and checklist, Insecta Mundi 2020 (788), pp. 1-88 : 23-24

Tetragonocephala flava Crawford, 1914

( Fig. 90, 91 )

Materials examined. USA: Florida: Specimens from Alachua, Miami-Dade, and Volusia counties ( FSCA, dry mounted, ethanol, envelope with dried leaves and lerps).

Diagnosis. Tetragonocephala flava can be recognized by the lerps on Celtis leaves ( Fig. 91 ). Lerps are clam shell shaped and open on the side. They are attached to the undersides of the leaves, often near forks in the leaf veins. Adults resemble the more common Pachypsylla species, but they are pale and have six dark spots on the mesonotum and one at the posterior tip of the scutellum ( Fig. 90 ).

Distribution. Tetragonocephala flava was described from the southern tip of Texas and is known from Mexico ( Ouvrard 2020). Its long presence in Florida, lack of serious damage to hosts, and the presence of a native parasite suggests that it is native to Florida. However, it possibly is adventive in Louisiana, where there was an outbreak that caused serious damage to the trees ( Solomon et al. 1997).

Florida distribution information. Tetragonocephala flava was recognized in Florida for the first time in April 1997 on Celtis laevigata Willd. in Oak Hill (Volusia County) (FSCA# E1997-1214) ( Halbert 1997b). Collectors were Avas Hamon, Ru Nguyen, Kenneth Hibbard, and L.J. Chambliss. Previously unrecognized specimens from Florida in the FSCA go back to 1957, when a specimen was collected at Snapper Creek Boy Scout Camp (Miami- Dade County) by sweeping Celtis . The exact date is unclear on the label, and no collector is mentioned. We have records, but no specimens, from Jacksonville (Duval County) collected 15.viii.1997 (FSCA# E1997-3281), Lake Jem (Lake County) collected 28.vii.1997 (FSCA# E1997-3438). The most recent collection was in Ft. Myers (Lee County) in June 2005, consisting of 6 empty lerps (FSCA# E2005-2972).

Host plants. Celtis laevigata Willd. (Cannabaceae) .

Comments. In Louisiana, major dieback of stands of C. laevigata was attributed to high populations of T. flava ( Solomon et al. 1997) . In Florida, no similar destruction of trees was observed, possibly because of a native parasite, Aprostocetus gelastus (Burks, 1943) (Eulophidae) , that controlled psyllid populations ( Halbert 1997a). More recently, the Asian aphid, Shivaphis celti Das, 1918 , ( Aphididae ) has become established on C. laevigata in Florida ( Halbert et al. 2000). This aphid is very abundant and may prevent build-up of populations of T. flava , which, based on submitted samples, has been rare since the establishment of S. celti in Florida.

Rhinocolinae Vondráček, 1957

Tainarys Brèthes, 1920

Figures

Figures 90, 91. Tetragonocephala flava. 90) Adult. 91) Fifth instar immature and lerps. (Photos by Jeff Lotz, FDACS-DPI).