Melanagromyza minimoides Spencer

Eiseman, Charles S., Lonsdale, Owen, Linden, John Van Der, Feldman, Tracy S. & Palmer, Michael W., 2021, Thirteen new species of Agromyzidae (Diptera) from the United States, with new host and distribution records for 32 additional species, Zootaxa 4931 (1), pp. 1-68 : 10-11

Melanagromyza minimoides Spencer

( Figs. 62–63 )

Material examined. IOWA: Winneshiek Co., Decorah, Will Baker Park , 10–13.viii.2017, em. by 16.viii.2017, J. van der Linden, ex Rudbeckia laciniata , # CSE4945 , CNC1643663–1643667 (2♁ 3♀) .

Hosts. Asteraceae : Borrichia frutescens (L.) DC., Helenium flexuosum Raf. , Helianthus annuus L., Heliopsis helianthoides Sweet , Melanthera nivea (L.) Small, Rudbeckia laciniata L. , Symphyotrichum simmondsii (Small) G.L.Nesom , Verbesina encelioides (Cav.) Benth. & Hook. f. ex A.Gray, V. virginica L.; Cucurbitaceae : Cucurbita foetidissima Kunth ; Urticaceae : Urtica dioica L. , U. gracilis subsp. holosericea (Nutt.) W.A.Weber ( Spencer & Stegmaier 1973; Steyskal 1980b; Spencer & Steyskal 1986; Shi & Gaimari 2015).

Larval biology. ( Figs. 62–63 ) On asteraceous hosts, larvae have been consistently reported as feeding in the seedhead. We noted individual disc florets of Rudbeckia laciniata turning brown before the other disc or ray florets had begun to wilt, and opening the affected florets revealed feeding damage to the developing achenes as well as excavations in the receptable.

Puparium. ( Fig. 63 ) Whitish-yellow, with black, strongly chitinized posterior spiracular processes, appreciably projecting beyond anal segment ( Spencer & Stegmaier 1973); formed in the seedhead.

Phenology and voltinism. This species is evidently multivoltine. The Iowa specimens emerged in mid-August, a few days after the puparia were collected. Adults have been reared in Ohio in mid-September ( Spencer & Stegmaier 1973), and in Maryland Steyskal (1980b) reported an adult emerging in December (indoors) from host material collected in November. Emergence dates of Florida specimens (reared under unknown conditions) include every month from November to March ( Spencer & Stegmaier 1973), and in southern California and Texas adults have been collected in May, with a reared specimen emerging on 1 July ( Shi & Gaimari 2015).

Distribution. USA: AR, CA, FL, *IA, MD, OH, TX; Mexico; Caribbean; South America ( Shi & Gaimari 2015).

Comments. Details are lacking for all of the purported rearing records of this species from non-asteraceous hosts. Steyskal (1980b) indicated that a single male (as Melanagromyza radicicola Steyskal ) had “emerged indoors from [a] root presumed to be of nettle, Urtica dioica L. ” collected in Maryland. According to Spencer (1990), this specimen was found dead in a rearing container and “[n]o puparium from which it might have emerged could be located. Earlier, specimens of M. minimoides had been reared in the same container from Heliopsis and Rudbeckia .” He thus concluded that the Urtica record was erroneous. Shi & Gaimari (2015) stated that M. minimoides has been reared from U. dioica subsp. holosericea in California, although this is not reflected in their listed label data. Their record from Cucurbita foetidissima is based on a single male labeled “ex. Cucurbita foetidissima (host plant), 1.VII.1963 ”; there is no indication of the larval feeding site or whether a puparium was found.

Figures

FIGURES 59–72. Mines and other feeding damage of Agromyzinae on host plants: 59: Agromyza aristata Malloch on Celtis laevigata; 60: Melanagromyza arnoglossi Eiseman & Lonsdale, spec. nov. on Arnoglossum sp.; 61: M. hieracii Eiseman & Lonsdale, spec. nov. on Hieracium scabrum; 62: M. minimoides Spencer on Rudbeckia lacinata; 63: same, section of flower head with puparia inside; 64: Ophiomyia abutilivora Spencer on Abutilon theophrasti; 65: same; 66: Melanagromyza verbenivora Eiseman & Lonsdale, spec. nov. on Verbena stricta, spiral gallery in stem with resulting leaf wilting; 67: same, affected seedhead; 68: Ophiomyia carolinensis Spencer on Symphyotrichum patens; 69: O. cf. frosti Spencer on Lactuca (puparium at upper right); 70: O. rugula Eiseman & Lonsdale, spec. nov. on Baccharis halimifolia; 71: same; 72: same, backlit, showing empty puparium.