Chenopodium, goosefoot

Dichotomous table for leafminers

Incl. Blitum.

1amine completely within a leaf => 2

1b mine partly in petiole or stem => 20

1c galls, etc => Tables for all parasites per species

2ablotch mine, no trace of an initial corridor => 3

2bcorridor, widening into a blotch => 10

2ccorridor throughout => 15

2dfleck mine => 17

2emine of indefinite shape, small (larvae with legs and feet; older larvae free, among spun leaves) => 18

3alarva with distinct head and feet => 4

3blarva a maggot; at start of the initial mine (larvae my change mines) a group of oval egg shells: Pegomya-species (nb: the larvae of P. conformis, exilis and interruptella are still undescribed) => 7

4a mine contains almost no frass; larva mines from an exterior silken tube: Scrobipalpa atriplicella

4bmine contains frass; larva lives within the mine => 5

5a mine brownish, often contracted by spinning into an indistinct tent; frass fine; elder larvae free in leaf cone: Calybites phasianipennella

5bmine white, flat; frass in black or green lumps or arcs; larvae remain in the mine until pupation => 6

6ablotch mine; frass in a big lump => 7

6bcorridor mine, densely, intestine-like coiled; frass in broad green fans: Chrysoesthia drurella

7a lowland species: Chrysoesthia sexguttella

7b mountain species: Chrysoesthia verrucosa

8alarva: lowest of the mandibular teeth exceptionally strong: Pegomya cunicularia

8blowest tooth not that oversized => 9

9aangle between terminal and subterminal mandibular teeth almost right:: Pegomya betae

9bthis angle very sharp: Pegomya hyoscyami

10amine brownish, often contracted by spinning into an indistinct tent; frass fine-grained; older larva lives free in a rolled leaf margin: Calybites phasianipennella

10bmine white or yellowish-green => 11

11alarva with distinct head and feet; mine full deep: Scrobipalpa nitentella

11blarva a maggot; mine at least partly under- or lower-surface => 12

12aprimary feeding lines distinct; frass in big lump => 7

12bno primairy feeding lines visible; frass in fine grains => 13

13airregular narrow corridor. rather abruptly widening ito a small blotch; at start of the mine at leaf lower-surface an egg shell (may fall off): Psilopa leucostoma

13binitial corridor reletively short and wide, merging into a large blotch; no egg shell => 14

14apuparium in the leaf (sometimes in a small mine of its own); mine with broad offshoots where greenish clouds of frass are deposited (sometimes only visibla after removasl of upper epidermis): Scaptomyza graminum

14blarva leaves the mine prior to pupation; frass sparse, in fine black grains: Amauromyza flavivfons

15acorridor full depth, strongly coiled, “intestine-like”; much green frass in arcs; larvae with distinct feet and head: Chrysoesthia drurella

15bcorridor upper- or lower-surface, not coiled; grass in black grains or strings; larva a maggot => 16

16apuparium in the mine (usuually in an lower-surface pupal chamber); frass in isolated grains: Chromatomyia horticola

16blarvae pupates after having left the mine; frass in strings: Liriomyza bryoniae

17 In the inflorescence of Chenopodium and other Amaranthaceae, especially when growing near the coast, lives a number of Coleophora species that feed on the developing fruits. Their cases are so similar that identification is possible only after breeding. Generally, they do not mine the leaves, and therefore are out of scope for this website. As far as the literature gives any information, the only species to be regarded as a leafminer is: Coleophora sternipennella

18a larva: pinacula colourless (the bases of the setae themselves are black) : Cnephasia incertana

18b pinacula black => 19

19a larva: behind/below the anus a chitinous comb: Cnephasia asseclana

19b anal comb absent: Cnephasia stephensiana

20amine in stem or midrib with offshoots into the leaf => 21

20bmine starts in a leaf; from there the larve penetrates the stem : Amauromyza chenopodivora

21alarva with distinct head and feet: Scrobipalpa obsoletella

21blarva a maggot: Delia echinata

Not included in the key: Amauromyza karli; Coleophora versurella; Liriomyza trifolii; Tuta absoluta.

mod 9.x.2017