Microbrachida perniciosae Caron, 2024

Caron, Edilson, Souza, Maria Geralda De & Pamblona, Ana Maria Santa Rosa, 2024, Rediscovery of Microbrachida Bierig, 1939, description of a new species from the Brazilian Amazon and its potential for biological control (Coleoptera, Staphylinidae), Zootaxa 5537 (4), pp. 541-550 : 546-549

Microbrachida perniciosae Caron , sp. nov.

( Figs 6–22 )

Type material. Holotype deposited in INPA. Labels : 1) “ BRAZIL, AM, Manaus, Centro de Pesquisa Agroflorestal da Amazônia Ocidental ( CPAA), 10.vii.2018, Maria Geralda de Souza, col.”; 2) “ Holotype, Microbrachida perniciosae Caron ”. 18 paratypes: 14 (7 INPA and 7 CESP) of them with the same first label of holotype, 4 ( CESP) with first label “ BRAZIL, AM, Manaus, AM 10 , Km 30, 05.ii.2019, Ricardo Rebello, col.”.

Diagnosis. Microbrchida perniciosae differs from M. gilvicornis in having body brownish to dark brown, with elytral suture region and abdominal segments III to V slightly lighter ( Fig. 6 ); head and pronotum subglabrous; antennomeres gradually darker from 8 to 11.

Description. Male. Maximum body length 1.5 mm, maximum elytral width 0.5 mm; Body brownish to dark brown, with elytral suture region and abdominal segments III to IV slightly lighter; appendices yellowish, with antennomeres darker gradually from 8 to 11. Head and pronotum subglabrous, elytra and abdomen with somewhat pubescence ( Fig. 6 ). Head strongly deflected; eyes very large, prominent.Antenna short, reaching base of pronotum ( Fig. 7 ). Mandibles asymmetrical, right with moderately internal tooh. Pronotum transverse, about twice wider than long. Elytra slightly longer than pronotum; apico-lateral angles markedly sinuate. Wings well-developed. Tergum VIII with two pairs of slender spiniform process, internal pair slender than external ( Fig. 11 ); sternum VIII broadly curved on posterior margin, somewhat pointed at medial three-fifths ( Fig. 14 ). Median lobe of aedeagus well sclerotized ( Figs 13 , 22 ); base bulbous; ventral surface with serrate area ( Fig. 21 ); cylindrical sclerotized flagellum slightly longer than apical lobe; compressor plate small and sclerotized; parameres long, when connected to median lobe exceed a little of it; apical lobe of paramerite about two times longer than wide.

Female. Similar to male, except posterior margin of tergum VIII slightly emarginated on medial two-thirds ( Fig. 15 ); posterior margin of sternum VIII more pointed at medial three-fifths ( Fig. 16 ); spermatheca sclerotized, neck elongate distal to latero-apical plate, apex very bulbous, slightly wider than long in lateral view ( Fig. 17 ).

Etymology. The specific name is a Latin adjective used as a noun in the genitive case and derived from the specific name of the fungus the new species is associated with: Moniliophthora perniciosa (Stahel) Aime & Phillips-Mora, 2005 . It causes an infection called witches' broom disease on trees of Theobroma . The term “perniciosa ” is treated as a noun ending with “- a ”, and then it receives “- ae ” in the genitive case. It is a particular case cited in ICZN (1999, art. 11.9.1.4).

Distribution. Brazil (Amazonas: Manaus).

Remarks. The specimens of M. perniciosae were collected associated with the mushroom Moniliophthora perniciosa , which were growing in living cupuassu trees [ Theobroma grandiflorum (Willd. ex Spreng.) K. Schum ].

The mushroom is a pathogenic endosymbiont of woody plants. It is responsible for the witches' broom disease ( Fig. 23, 25 ) and has been already found in 29 hosts in Brazil, including five species of Theobroma ( Lisboa et al. 2020) .

Microbrachida perniciosae adults were taken from Moniliophthora perniciosa basidiocarps ( Figs 24, 26, 27 ), and no other species were found on them. A predatory relationship with the fungus propagules is suggested by the damage these insects caused to the basidiocarps ( Fig. 28 ). Such spore feeding behavior may be important to reduce the inoculum of the witches' broom fungus, considering that spores are the main infective type of the pathogen ( Bastos & Andebrhan 1987, Evans et al. 2013). However, additional research is required to determine whether M. perniciosae may also act as dispersers if and when the spores are carried on their bodies or continue to be viable after passing through their intestines ( Tuno 1999).

Figures

FIGURES 6–7. Microbrachida perniciosae. 6. Habitus, dorsal view; 7. Habitus, lateral view; Scale bars: 1mm.

FIGURES 8–17. Microbrachida perniciosae. 8. Labrum, dorsal view; 9. Maxilla, dorsal view; 10. Labium, ventral view; 11. Tergite VII, male, dorsal view; 12. Tergite IX and X, male, dorsal view; 13. Median lobe of aedeagus, lateral view; 14. Sternite VIII, male, ventral view; 15. Tergite VIII, female, dorsal view; 16. Sternite, female, ventral view; 17. Spermatheca. Scale bars: 8, 10 = 0.03 mm; 9–16. = 0.125mm; 17 = 0.06 mm.

FIGURES 18–22. Microbrachida perniciosae. 18. Antena; 19. Elytra; 20. Meso- and Metaventrite; 21. Detail of median lobe of aedeagus; 22. Median lobe of aedeagus. Scale bars: 19–20, 22 = 100 micrometers; 21 = 10 micrometers.

FIGURES 23–28. 23. Cupuassu tree infected with witch’s broom symptoms. 24. Basidiocarps on necrotic witch’s brooms in cupuassu tree. 25. Dried pods with witch’s broom symptoms in cupuassu tree. 26. Adult Microbrachida perniciosae forage on basidiocarps. 27. Adults of Microbrachida perniciosae on basidiocarps; 28. Damages on basidiocarp caused by Microbrachida perniciosae.